Fix error NotImplemented for Windows OS

CHANGES.txt

@@ -1,3 +1,9 @@
+1.3.2b2 (2021-09-29)
+^^^^^^^^^^^^^^^^^^^^
+
+* Fix error NotImplemented for Windows OS and Python >= 3.8 `#881 <https://github.com/aio-libs/aiopg/pull/881>`_
+
+
 1.3.2b1 (2021-07-11)
 ^^^^^^^^^^^^^^^^^^^^
 

aiopg/utils.py

@@ -14,7 +14,25 @@
     Union,
 )
 
-if sys.version_info >= (3, 7, 0):
+
+def is_win_os() -> bool:
+    return sys.platform == 'win32'
+
+
+class PythonVersion:
+    @staticmethod
+    def is_38_or_high() -> bool:
+        return sys.version_info >= (3, 8, 0)
+
+    @staticmethod
+    def is_37_or_high() -> bool:
+        return sys.version_info >= (3, 7, 0)
+
+
+if PythonVersion.is_38_or_high() and is_win_os():
+    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
+    __get_running_loop = asyncio.get_running_loop
+elif PythonVersion.is_37_or_high():
     __get_running_loop = asyncio.get_running_loop
 else: